Externally control Growatt SPH 3600 via RS485/Modbus

[JojoB]

Hi,

I am looking for a way to control various parameters of a Growatt SPH 3600 via RS485/Modbus. Specifically, I want to control the working mode (LoadFirst, BatteryFirst, GridFirst) and the AC charge (activation/power) of the battery depending on the current and planned power demand or price. It is probably not a good idea to constantly change the holding registers in the EEPROM. Does anyone know another way to control this externally?

Many thanks in advance!

 

[geosol]

Hi,
A way to get better control of Growatt SPH xxxx BH-UP in mode LoadFirst is to set ExporLimit On and Export Power set to zero . You add a small electronic box between power meter (DTSU666 ?) and inverter (RS485 protocol ) in order to shift the meter power :
when the meter measures power P, the electronic box sends ( P+Pshift) to inverter . This allows to modifiy every time the export power to -Pshift (without changing holding register) . The value of Pshift (positive or negative) is controlled by software and can be depending on many parameters . I have made a such electronic box for less than 20 $ .

 

[GSXR1000]

Hi,

I am looking for a way to control various parameters of a Growatt SPH 3600 via RS485/Modbus. Specifically, I want to control the working mode (LoadFirst, BatteryFirst, GridFirst) and the AC charge (activation/power) of the battery depending on the current and planned power demand or price. It is probably not a good idea to constantly change the holding registers in the EEPROM. Does anyone know another way to control this externally?

Many thanks in advance!

solar assistant will do that with my growatt 3000 spf

 

[thetorque]

Hi,
A way to get better control of Growatt SPH xxxx BH-UP in mode LoadFirst is to set ExporLimit On and Export Power set to zero . You add a small electronic box between power meter (DTSU666 ?) and inverter (RS485 protocol ) in order to shift the meter power :
when the meter measures power P, the electronic box sends ( P+Pshift) to inverter . This allows to modifiy every time the export power to -Pshift (without changing holding register) . The value of Pshift (positive or negative) is controlled by software and can be depending on many parameters . I have made a such electronic box for less than 20 $ .

That's such an interesting idea. I have a few questions related to your suggestion.

If I understand correctly, the energy meter is measuring the power right behind the electrical grid (the summing point, i.e., load + inverter power). When the system has achieved zero export, the energy should measure 0 watts, no? So if you add an offset (called Pshift), then the feedback loop of the inverter will keep trying to compensate until it reaches max power? since the energy meter will never read zero.

I feel like it's doable but maybe I'm missing something.

 

[thetorque]

Hi,

I am looking for a way to control various parameters of a Growatt SPH 3600 via RS485/Modbus. Specifically, I want to control the working mode (LoadFirst, BatteryFirst, GridFirst) and the AC charge (activation/power) of the battery depending on the current and planned power demand or price. It is probably not a good idea to constantly change the holding registers in the EEPROM. Does anyone know another way to control this externally?

Many thanks in advance!

I have been trying to control the working mode through changing the register but had no luck so far. Can you share some information regarding this? I can read parameters from RS485 but cannot set them.

 

[WOLF-GANG]

I guess I would go the homeassistand and grott route.
Grott is acting like a proxy and listens to what goes to the cloud and also offers to access and manipulate the registers afaik.
Grott is opensource and there is a lot going on if you check github carefully.

I have upgraded my smaller mic600 to mic 2000 or from 600W to 2000W just by changing a register due to their certification of several inverters (family=) under 1 certificate. You can buy the smallest and "pimp" the performance to the highest of those on the certificate. 4600 can become 6000 which means a good boost.